Bearing



P. E. BARKER Sqn. 4, 1934.

BEARING Filed Oct. 26.A 1931 .r f .Ill

abbonmq Patented Sept. 4, 1934` BEARING `Percy E. Barker, Towson, Md.,assigner to The Black & Decker Manufacturing Company, f

Towson, Md., a corporation of Maryland Application October 26,

voisins.

` In accordance with the existing practice regarding the mounting ofrotating shafts on ball bearings, the rotor shaft of an electric motorbeing a convenient example, the outer race of one -5 bearing is heldrigid in the bearing housing into which it is ordinarily pressed orforced, while the other bearing is left free to slide, i. e., in thedirection of the axis, to take up expansion and contraction of theshaft, the outer race having what is known as a sucking fit in the seator housing.

In the manufacture of these parts absolute accuracy is impossible. Inthe manufacturing practice there are therefore certain tolerances orvariations permitted in machining as tc the diameter of the seat and theouter diameter of the outer race, and under certain conditions as whenthe inside diameter of the seat is near the upper limit and the outsidediameter of the outer race is near the lower limit, the engagement ofvthe outer race with the seat is apt to be so loose that the outerracerotates with the inner race and ball retaining cage and shaft sothat some of the parts actually within the proper inspection limitscannot be used satisfactorily together.

The object of the present invention is to make it feasible to use allbearings and seats within the regular tolerances and to even increasethe tolerance as to the diameter of the seat bore and the outsidediameter of the outer race in the direction of the maximum diameter ofthe former and the minimum diameter of the latter or t0 otherwise varyor increase the difference between the diameter of the race and seat,and still establish a relation of the parts which has all the at thesame time allows it to move in the direction of the axis with sumcientfreedom to take up the expansion and contraction of the shaft,eliminating any tendency to cramp the bearings on account of suchcontraction and expansion, and in case the bearing race starts, asv itmay, to creep or rotate very slowly, a certain amount of rubber will bedeposited on its surface and accumulate between the surfaceof the raceand The rubber contacting 1931, serial No. 510,991

the housing bore tending to assist the rubber supports in holding therace against rotation.

By virtue of the invention the necessity for the sucking fit of the racein the seat which is a matter of some considerable e'xpense, is in 60elect dispensed with, or'` made unnecessary, cheapening the product andfacilitating its manufacture.

In the accompanying drawing I have illustrated a bearing supportembodying the features of the invention in connection with so much of anelectric motor equipped with the bearing support as is necessary to anunderstanding of the invention, and the lmethod of applying the same.

In the drawing:

Figure 1 is an elevation partly in section of a motor housing and amotor equipped with the bearing support of the invention.

Figure 2 is a section on the line V2, 2 of Figure 1.

Referring to the drawing by numerals, each of. which is used to indicatethe same or similar -parts in the diierent' figures, the constructionshown comprises a motor housing or frame 1, enclosing the motor 2 havinga rotor 3 mounted in a shaft 4 which rotates in ball bearings 5 80 and6, at each end. One bearing 5 is stationary and has its outer race 'Irigidly secured in the seat 8 into which it is forced or pressed. Theother bearing 6, on the other hand, ,has its outer race 9 mounted toslide in the seat 10 in the 95 direction of the axis of the shaft 4 totake up and provide for longitudinal expansion and contraction of themotor shaft 4 as its temperature `rises and falls;A it being understoodthat in accordance with the usual practice the inner race 11 is securedto the shaft 4 and the inner and outer races are provided withregistering grooves 12 and 14, respectively, in which the balls 15 areseated so that the bearing balls 15 provide a connection between theinner and outer races and the shaft 4, causing the bearing to move ortend to move back and forth in the direction of the axis as the shaftexpands which is the method whereby the contraction and expansion of theshaft are taken up by the sliding bearing which isf/the subject of theinvention.

In accordance with the construction shown,

ltheseat 10 for the sliding or oating bearing 6 is enclosed in a housingor boss 16 formed on the frame or motor housing 1.

This housing or boss 16 in the form of the invention shown is drilled orapertured radially or in any suitable manner at 1'7 with a plurality ofholes extending' from the outside of the "boss 16 into the scat orcavity 10, there beingthree 110' 5 \A screw 20 inwardly disposed towardthe bearing seat 21, is engaged with th'e thread in each opening or bore1'7, each screw being preferably a little shorter than the distance fromthe top of the boss 19 to the outside ofthe outer baal race 9 and asmall cylinder or block of liverubber 22 is placed in each bore or'opening 1'1, between the end of the corresponding screw 20 and theouter surface of the outer ball race s). The rubber cylinder or blockbeing preferably cf such a thickness that when the screw is insertedVand tightened up against the lock washer 24 or the outer surface of theboss 25, there being pref- Aerably some sort of stop to position thescrew,

an appreciable y pressure will be applied to the rubber cylinder.

The rubber thus contacting with the outside.

of the ball bearing race 9 tends to apply a dragging tendency to itwhich prevents the race from rotating but allows it to slide withsufficient freedom in the direction of the axis to take up or providefor the expansion and contraction of the shaft without causing crampingof the bearings 5, 6.

In case the outer race 9 starts to creep or rotate, a certain amount ofrubber will be deposited on its surface and tend to accumulate betweenthe surface of the Lrace and the housing wall, thus contributing totheeffect of the rubber cylinders in holding it against rotation.

Preferably the outer race is supported and guided by the seat, thefriction member serving merely to prevent free rotation of the race atthe same time permitting the race to yield longitudinally to provide forcontraction and expansion of the shaft.

I have thus described specifically and in detail a` bearing supportparticularly adapted to use with ball bearings, embodying the featuresof my invention in the preferred form in order that the manner ofconstructing, applying, operating and using the invention may be fullyunderstood, however, the specific terms herein are used descriptivelyrather thanin a limiting sense, the

scope of the. invention being delned in the claims.

What claim as new anddesire to secure by.

Letters Patent is:

l. The combination with a ball bearing for a 'rotary shaft, the ballbearing having an inner and outer race with registering grooves andballs ltherein, of a seat for the outer race-in whichit is mounted toslide and in which it is rotatable, and yielding means in the form ofrelatively soft solid material in contact with the outer race and va.plurality of inembers arranged to operate in radial directions andspaced along the periph- 'ery adapted to adjust the pressure. on saidsoft material for applying friction to the outer race tending torestrain rotation of the outer race and permitting it to yield inthedirection of the axis ofthe shaft. v v

2. The combination with a ball bearing for a rotary shaft, the ballbearing having an inner and outer -race with registering grooves andballs therein,'of a seat for the outer race in which it may rotate andin which it is mounted to slide, and adjustable means spaced about theperiphery 1,972,581 of said holes 17 in the form of the inventionvr ofthe race to operate in a radial direction for applying friction to theouter race tending to prevent rotation of the outer race and permittingit to yield in the direction shaft said means for applying frictionincluding a plurality of blocks `of soft material in contact with theouter race and similarly spaced.

3. 'Ihe combination with a ball bearing for a shaft having an inner andouter race with registering grooves and balls therein of a cylindricalseat for the outer race in which the race is mounted to slide and inwhich it may rotate, and

yielding means comprising a pad of soft material engaging the race andan adjustable member engaging the pad in a radial direction for applyingpressure to the outer surface thereof, tending to prevent rotation ofthe race and permitting it to yield in the direction of the axis of theshaft.

4. 'I'he combination with a ball bearing having inner and outer raceswith registering peripheral grooves and balls therein, the outer racehaving a fullv cylindrical peripheral surface a cylindrical seat for theouter race in which it is adapted to slide in the direction of the axisof the bearing and in which it is rotatable, said seat having threadedopenings4 arranged in a substantially radial direction, yieldingmaterial in said openings engaging the outer race, checking the rotationthereof and permitting to to slide axially, and screws for applyingpressure thereto, and abutments whereby the screws are positioned insaid openings to vdetermine the pressure.

5. The combination with a ball bearing for a rotary shaft having innerand outer races with registering grooves, and balls therein of acylindrical 'seat concentric with the outer race, the seat havingapertures with resilient blocks therein, and means for applying pressureto said blocks,A said pressure being transmitted to the outer race toprevent rotation thereof, permittingit to yield in the direction of theaxis of the bearing without cramping the bearing.

)time un or the 6. The combination with a ball bearing for a A rotaryshaft having inner and outer races with registering grooves and ballstherein of a cylinto prevent rotation thereof and permitted to yield iin the direction of the axis of the bearing without cramping thebearing, the pressure applying means beingin the 'form of a screwengaging each block and an abutment for limiting theadvance of thescrew.

'7. 'I'he combination with a ball bearing for a rotary shaft havinginner and outer racesl with registering grooves and balls therein of acylindrical seat concentric with the outer race, the seat havingapertures with rubber blocks therein and means for applying pressure tosaid blocks, said pressure being transmitted to the outer race toprevent rotation thereof and permitted to yield in the direction of theaxis of the bearing without cramping the bearing, the pressure applyingmeans being in the form of a screw engaging each block and an abutmentfor limiting the advance of the screw, the threaded apertures beingspaced by of the seat.

PERCY E. Banana.

